The first chemical synthesis of F-4-GlcAβ(1→3)GlcNAc-UDP with the potential of novel substrate and enzyme inhibitor for hyaluronic acid synthases (HASs)

Article abstract of DOI:10.1016/j.tetlet.2009.08.017

The first chemical synthesis of F-4-GlcAβ(1→3)GlcNAc-UDP is described here. This compound can serve as a novel substrate to study the catalytic mechanism of hyaluronic acid synthases (HASs) and has potential to be donor for these enzymes that extend HA ch

Full text of DOI:10.1016/j.tetlet.2009.08.017

Tetrahedron Letters 50 (2009) 5920–5922
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Tetrahedron Letters
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The first chemical synthesis of F-4-GlcAb(1?3)GlcNAc-UDP with the potential
of novel substrate and enzyme inhibitor for hyaluronic acid synthases (HASs)
Guohua Wei a,b, Vipin Kumar a, Jun Xue a, Robert D. Locke a, Khushi L. Matta a,
*
a Cancer Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
b State key laboratory of Environmental Chemistry and Ecotoxicology, Research center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
a r t i c l e i n f o
a b s t r a c t
Article history:
The first chemical synthesis of F-4-GlcAb(1?3)GlcNAc-UDP is described here. This compound can serve
as a novel substrate to study the catalytic mechanism of hyaluronic acid synthases (HASs) and has poten-
tial to be donor for these enzymes that extend HA chain at the reducing end. Moreover, it may also
behave as inhibitor for the enzymes that act on non-reducing end in the assembly of HA chain.
Ó 2009 Elsevier Ltd. All rights reserved.
Received 7 July 2009
Revised 4 August 2009
Accepted 9 August 2009
Available online 13 August 2009
Keywords:
F-4-GlcA
Hyaluronic acid synthases (HASs)
Oligosaccharides
Phosphates
1. Introduction
Hitherto, no three-dimensional structure for any HASs is available,
therefore, our understanding of the detailed mechanisms whereby
Hyaluronan (HA),
a
non-sulfated linear glycosaminoglycan
hyaluronan influences cell behavior is still very incomplete.3
Interfacing chemistry between biology4 has been the real guide
and theme for our laboratories over the last three decades. A chem-
ical synthetic approach provides a series of well-defined oligosac-
charide structures that can lead to the identification of the
previously unrecognized glycosyltransferases activities and, there-
fore, to the discovery of new biosynthetic pathways in the assembly
of glycans. The modifications to the basic acceptor structures by the
introduction of O-Me or fluoro groups can result in highly specific
acceptors or inhibitors for the individual glycosyltransferases. In
this context, a series of novel acceptors have been synthesized to
study sulfotransferases, sialyltransferases, and fucosyltransferases.5
We now extend our theme of interfacing chemistry between biology
of HA to focus our attention on development of tools to understand
the metabolism of this molecule. We describe herein the first chem-
ical synthesis of F-4-GlcAb(1?3)GlcNAc-UDP (1) which may have
the potential to be a specific donor for the HASs enzyme that extend
the HA chain at the reducing end whereas this modified analog may
function as inhibitor for the enzyme that act at non-reducing end in
the assembly of HA molecule.
(GAG) polymer, composed of repeating disaccharide units of glucu-
ronic acid and N-acetylglucosamine linked together via alternating
b-1,4 and b-1,3 glycosidic bonds. It is one of the chief components
of the extracellular matrix and contributes significantly in multiple
biological and physiological functions such as wound healing,
inflammation, angiogenesis, and tumor growth.1 Hyaluronan syn-
thases (HASs) are the enzyme which catalyze the polymerization
of HA using UDP-sugar precursors. These are the first glycosyl-
transferases, unlike the majority of other known glycosyltransfer-
ases, demonstrated to be capable of transferring two distinct
sugars (GlcUA and GlcNAc) alternatively only to one end of grow-
ing HA polymer chain.1a,e,2 This unique bifunctional nature of HASs
in the assembly of HA molecule is recently reviewed by Weigel
et al.3 Added to the inimitability of these enzymes, there are two
mutually exclusive possibilities for the direction of HA biosynthe-
sis. Bacterial HASs add sugars at the non-reducing ends of the
acceptor to produce the HA polymer, whereas, vertebrate enzymes
transfer the sugars to the reducing end (Fig. 1). For the biosynthesis
at the reducing end, the UDP released during each transfer step
comes from an HA-UDP intermediate formed by addition to the
previous sugar.1e,2,3 The intermediate, (HA)-UDP, acts at the C-3
position of UDP-GlcNAc releasing the UDP of HA, and keeping the
UDP of GlcNAc intact. This divergence calls for an explanation.
extension at the
reducing end
extension at
non reducing end
GlcUAβ3GlcNAcβ4GlcUAβ3GlcNAcβ
Vertebrate enzymes
Figure 1. Extension of HA polymer.
Bacterial enzymes
* Corresponding author. Tel.: +1 716 845 2397; fax: +1 716 845 8768.
E-mail address: khushi.matta@roswellpark.org (K.L. Matta).
0040-4039/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2009.08.017

G. Wei et al. / Tetrahedron Letters 50 (2009) 5920–5922
5921
O
N
The synthesis of 3 commenced with compound 5, which was
treated with diethylaminosulfur trifluoride (DAST)8 followed by
deprotection of benzoyl groups to afford 6 in 85.4% yield (over over
two steps). Selective oxidation of 6-OH of 6 to a carboxylic acid by
HO
HO
NH
HOOC
O
O
F
O
O
P
O
P
O
O
HO
AcHN
9
OH
O
O
O
2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and Ca(ClO)2 fol-
OH OH
lowed by methyl esterification and benzoylation gave 7 with 82%
overall yield in three steps. Chemoselective removal of NAP with
DDQ10 and subsequent treatment with trichloroacetonitrile in the
presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) afforded
imidate 3 in 78% yield.11 Next, synthesis of monosaccharide accep-
tor 4 was initiated using already known compound 8.6 Installation
of isopropylidene group and subsequent acetylation provided 9 in
good yield. Treatment of 9 with 80% HOAc to remove the isopropyl-
idene followed by benzoylation gave 10 in high yield. Finally, selec-
tive removal of 3-OAc group of 10 with p-TsOH in CH2Cl2–MeOH
(9:1) proceeded smoothly12 to afford 4 in 89% yield (Scheme 1).
With the required building blocks in hand, the multistep syn-
thesis of the phosphate 2 was initiated. First, coupling of the F-4-
GlcA donor 3 and the suitable protected acceptor 4 was carried
out with BF3ꢀEt2O in the presence of 4 Å molecular sieves in tolu-
ene to give the desired disaccharide 11 with complete b1?3 stere-
oselectivity in 89% yield.7a,8,13 Substitution of dichloromethane as a
solvent proved to be detrimental for above-mentioned glycosyla-
tion reaction. Also, TMSOTf was found ineffective for the same gly-
cosylation as a promoter in comparison with BF3ꢀEt2O. Not many
expedient methods are available for the synthesis of GlcAb1?3
linkage8,13b–e and suffer from certain drawbacks. For example, a
OH
HO
1
BzO
BzO
O
MeOOC
O
O
F
O
P
BzO
AcHN
O
OBz
OBn
OBn
2
MeOOC
BzO
BzO
HO
O
O
+
F
ONAP
BzO
BzO
TrocHN
OC(NH)CCl3
3
4
Figure 2. Retrosynthetic analysis of target compound F-4-GlcAb(1?3)GlcNAc-
UDP 1.
2. Results and discussion
As shown in retrosynthetic analysis (Fig. 2), the key intermedi-
ate in our approach to the title compound 1 is the protected F-4-
GlcAb(1?3)GlcNAc-1-phosphate derivative (2) that could be de-
rived from monosaccharide building blocks 3 and 4. For the prep-
aration of 3 and 4, NAP as an anomeric protecting group attracts
our attention as this group, like p-methoxybenzyl, can be mildly
removed with DDQ oxidation (reported from our laboratory). It
may be added here that many starting monosaccharides having
NAP group did not require chromatography. Moreover, the com-
pounds being solid were easy to handle.6 The preference of benzoyl
group over acetyl group for protection of the 2-OH position of GlcA
in donor 3, circumvented the possible formation of side product
due to transacetylation during O-glycosylation.7
synthesis reported by Kong and co-workers yielded both
a- and
b1?3 linked products in equimolar ratio.13b Withers and co-work-
ers followed an alternative route, to obtain F-4-GlcAb1?3 linked
disaccharide. First, the synthesis of F-4-Glcb1?3 linked disaccha-
ride was carried out followed by oxidation of F-4-Glc moiety to
achieve final product. However, the overall yield of this indirect
conversion was only moderate.8 Similar roundabout synthetic
sequence was also accounted by Yeung et al.13c Fraser-Reid and
co-workers utilized GlcA imidate donor to glycosylate 3-OH of
suitably protected n-pentenyl acceptor but resulted in 3:1 mixture
of the desired b1?3 linked disaccharide and the corresponding
orthoester.13d Recently, Rele et al. reported
a stereospecific
HO
BzO
OBz
O
OH
O
MeOOC
c
a
d
b
O
F
3
4
F
ONAP
ONAP
ONAP
ONAP
BzO
HO
BzO
OBz
OH
6
5
7
OH
O
BzO
BzO
AcO
O
f
e
O
O
O
HO
HO
ONAP
ONAP
AcO
TrocHN
TrocHN
NHTroc
9
8
10
Scheme 1. Preparation of the key building blocks 3 and 4. Reagents and conditions: (a) (i) DAST, CH2Cl2, ꢁ30 °C, 4 h, 89%; (ii) NaOMe, MeOH, rt, 4 h, 96%; (b) (i) TEMPO,
Ca(ClO)2, KBr, Bu4NBr, CH2Cl2, satd aq NaHCO3, 0 °C, 1 h; (ii) MeI, KHCO3, DMF, rt, 10 h; (iii) BzCl, py, rt, 4 h, 82% for three steps; (c) (i) DDQ, CH2Cl2–MeOH (4:1), rt, 12 h; (ii)
CCl3CN, DBU, CH2Cl2, 0 °C, 2 h, 78% for two steps; (d) (i) 2,2-dimethoxylpropane, p-TsOH, DMF, 0 °C, 4 h; (ii) Ac2O, py, rt, 4 h, 88% for two steps; (e) (i) 80% HOAc, 70 °C, 4 h; (ii)
BzCl, py, rt, 4 h, 92% for two steps; (f) p-TsOH, CH2Cl2–MeOH (9:1), rt, 24 h, 89%.
BzO
BzO
MeOOC
MeOOC
b
a
O
O
O BzO
O
BzO
F
ONAP
3 + 4
F
ONAP
O
O
O
BzO
BzO
AcHN
TrocHN
BzO
BzO
12
11
BzO
c
d
MeOOC
2
O
BzO
F
O
OH
BzO
AcHN
BzO
13
Scheme 2. Preparation of disaccharide monophosphate derivative 2. Reagents and conditions: (a) BF3ꢀEt2O, toluene, 4 Å MS, 0 °C, 2 h, 89%; (b) Zn, Ac2O, AcOH, THF, rt, 3 h,
86%; (c) DDQ, CH2Cl2–MeOH (4:1), rt, 12 h, 89%; (d) LHMDS, [(BnO)2P]2O, THF, ꢁ70 to 0 °C, 3 h, 83%.

5922
G. Wei et al. / Tetrahedron Letters 50 (2009) 5920–5922
2. Prehm, P. Biochem. J. 2006, 398, 469.
BzO
MeOOC
O
3. Weigel, P. H.; DeAngelis, P. L. J. Biol. Chem. 2007, 282, 36777.
4. Newman, R. H.; Zhang, J. Nat. Chem. Biol. 2008, 4, 382.
a
b
BzO
O
2
F
1
O
O
P
BzO
AcHN
5. (a) Xia, J.; Xue, J.; Locke, R. D.; Chandrasekaran, E. V.; Srikrishnan, T.;
Matta, K. L. J. Org. Chem. 2006, 71, 3696; (b) Chandrasekaran, E. V.; Xue,
J.; Xia, J.; Chawda, R.; Piskorz, C.; Locke, R. D.; Neelamegham, S.; Matta,
K. L. Biochemistry 2005, 44, 15619; (c) Chandrasekaran, E. V.; Lakhaman,
S. S.; Chawda, R.; Piskorz, C. F.; Neelamegham, S.; Matta, K. L. J. Biol.
Chem. 2004, 279, 10032; (d) Chandrasekaran, E. V.; Jain, R. K.; Matta, K.
L. J. Biol. Chem. 1992, 267, 23806.
OBz
O
OH
O
Et3NH
14
Scheme 3. Synthesis of F-4-GlcAb(1?3)GlcNAc-UDP 1. Reagents and conditions:
(a) H2, Pd–C, EtOAc–MeOH (1:1), Et3N, rt, 6 h, 91%; (b) (i) UMP-morpholidate, 1H-
tetrazole, DMF-py (3:1), rt, 2 d; (ii) 3 M NaOH, MeOH, rt, 10 h; (iii) RP column HPLC;
gel-filtration column HPLC, 42% from 14.
6. (a) Xue, J.; Khaja, S. D.; Locke, R. D.; Matta, K. L. Synlett 2004, 5, 861; (b) Xue, J.;
Kumar, V.; Khaja, S. D.; Chandrasekaran, E. V.; Locke, R. D.; Matta, K. L.
Tetrahedron 2009, in press, doi:10.1016/j.tet.2009.07.089; (c) Compound 8 was
prepared according to the method described in: Vauzeilles, B.; Dausse, B.;
Palmier, S.; Beau, J.-M. Tetrahedron Lett. 2001, 42, 7567.
synthesis of b1?3 linked disaccharide by the glycosylation of n-
pentenyl glycoside acceptor with GlcA donor without obtaining
the corresponding orthoester as the side product.13e In conclusion,
the efficacy of glycosylation with a donor can depend on the nature
of the sugar alcohol and the protecting groups present there in.
Thus, it is also perceptible from above discussion that the glycosyl-
ation reaction described by us is extremely efficient and superior to
most of the previously described syntheses for b1?3 linkage. Our
glycosylation reaction provides a route to obtain F-4-GlcAb1?3
linked disaccharide with complete b1?3 stereoselectivity and high
yield.
7. (a) Brown, R. T.; Carter, N. E.; Mayalrap, S. P.; Scheinmann, F. Tetrahedron 2000, 56,
7591; (b) In a separate study in our laboratory, the reaction of commonly used
methyl 2,3,4-tri-O-acetyl-1-O-trichloroacetimidoyl-
nate with NAP 2,4,6-tri-O-benzoyl-b- -galactopyranoside did not proceed to
give the desired b1?3 disaccharide in a satisfactory yield but afforded the
transacetylated product viz., NAP 3-acetyl-2,4,6-tri-O-benzoyl-b- -galactopy-
ranoside. Hence, it is evident that the glycosylation with GlcA donor can depend
upon the nature of the acceptor also.
a/b-D-glucopyranosyluro-
D
D
8. Rye, C. S.; Withers, S. G. J. Am. Chem. Soc. 2002, 124, 9756.
9. Lin, F.; Peng, W.; Xu, W.; Han, X.; Yu, B. Carbohydr. Res. 2004, 339, 1219.
10. Xia, J.; Abbas, S. A.; Locke, R. D.; Piskorz, C. F.; Alderfer, J. L.; Matta, K. L.
Tetrahedron Lett. 2000, 41, 169.
To proceed further in our synthetic sequence, NHTroc group of
11 was transformed to NHAc using Zn–Ac2O to furnish 12 in 86%
yield. Selective removal of NAP with DDQ in CH2Cl2–MeOH (4:1)
and subsequent phosphorylation with tetrabenzyl pyrophospgate14
11. Schmidt, R. R.; Michel, J. Angew. Chem., Int. Ed. Engl. 1980, 19, 731.
12. González, A. G.; Brouard, I.; León, F.; Padrón, J. I.; Bermejo, J. Tetrahedron Lett.
2001, 42, 3187.
13. (a) Schmidt, R. R. Angew. Chem., Int. Ed. Engl. 1986, 25, 212; (b) Chen, L.; Kong, F.
Carbohydr. Res. 2002, 337, 1373; (c) Yeung, B. K. S.; Hill, D. C.; Janicka, M.;
Petillo, P. A. Org. Lett. 2000, 2, 1279; (d) Allen, J. G.; Fraser-Reid, B. J. Am. Chem.
Soc. 1999, 121, 468; (e) Rele, S. M.; Iyera, S. S.; Chaikof, E. L. Tetrahedron Lett.
2007, 48, 5055.
gave the benzyl-protected anomeric phosphate 2 as the desired
a
anomer in high yield. Appearance of significant signals in the 1H
NMR spectrum of 2 at d = 5.71 (dd, J1,2 = 3.4 Hz, J1,P = 6.4 Hz, 1H,
H-1of GlcNAc), and the signal in the 13P NMR of 2 at d = ꢁ1.91 (s,
1P) confirmed that the newly formed linkage between the disaccha-
14. Takaku, H.; Ishida, H.-k.; Fujita, M.; Inazu, T.; Ishida, H.; Kiso, M. Synlett 2007,
818. and references cited therein.
15. The selected physical data of key compounds is listed: Compound 3: ½a D25
ꢂ
+8.9 (c
0.9, CHCl3); 1H NMR (400 MHz, CDCl3): d (ppm) = 3.86 (s, 3H, COOMe), 4.50
(dd, J5,4 = 9.6 Hz, J5,F = 4.8 Hz, 1H, H-5), 5.01 (ddd, J4,3 = 10.0 Hz, J4,F = 49.6 Hz,
1H, H-4), 5.19 (dd, J2,1 = 4.0 Hz, J2,3 = 9.6 Hz, 1H, H-2), 6.11 (ddd,
J3,2 = J3,4 = 10.0 Hz, J3,F = 14.6 Hz, 1H, H-3), 6.62 (d, J1,2 = 3.6 Hz, 1H, H-1),
ride and phosphoric acid moiety was
a (Scheme 2).
Deprotection of the benzyl groups in compound 2 by hydroge-
nation over Pd–C provided 14 in very high yield. Coupling of 14
with UMP-morpholidate in the presence of 1H-tetrazole in DMF–
pyridine (3:1)14 followed by deprotection of the benzoyl groups
and the methyl ester using 3 M NaOH afforded the target com-
pound 115 in 42% yield over two steps after isolation and purifica-
tion by reverse-phase column HPLC and gel-filtration column HPLC
(Scheme 3).
7.35–8.01 (m, 10H, Ph), 8.87 (s, 1H, NH). 13C NMR (100 MHz, CDCl3)
d
(ppm) = 52.5, 69.4, 71.6 (d, J = 18.0 Hz), 72.3 (d, J = 17.7 Hz), 86.3 (d, J = 17.7 Hz,
C-4), 90.1, 92.3, 159.7, 164.7, 164.9, 167.5. MALDITOF-MS: calcd for
C23H19Cl3FNO8: 561.02; found: 584.34 [M+Na]+. Compound 4: ½a D25
ꢂ
+52.5 (c
1.3, CHCl3); 1H NMR (400 MHz, CDCl3)
d (ppm) = 3.21 (s, 1H), 3.85 (t,
J = 10.6 Hz, 1H), 4.22 (m, 1H), 4.35 (m, 2H), 4.45 (dd, J = 4.6, 11.5 Hz, 1H),
4.58 (d, J = 12.0 Hz, 1H), 4.65 (d, J = 12.0 Hz, 1H), 4.72 (m, 2H), 4.88 (d,
J = 8.6 Hz, 1H), 5.15 (d, J = 9.0 Hz, 1H), 5.63 (t, J = 9.6 Hz, 1H), 6.90–8.0 (m, 17H).
MALDITOF-MS: calcd for C34H30Cl3NO9: 701.10; found: 724.45 [M+Na]+.
Compound 11: ½ ꢂ d
a 2D5 +20.6 (c 0.7, CHCl3); 1H NMR (400 MHz, CDCl3)
(ppm) = 3.39 (s, 3H), 3.95–3.98 (m, 2H), 4.35–4.41 (m, 2H), 4.51–4.57 (m,
2H), 4.60 (d, J = 7.8 Hz, 1H, H-10), 4.62–4.68 (m, 2H), 4.78–4.80 (m, 1H), 4.83 (d,
J = 8.0 Hz, 1H, H-1), 4.95 (d, J = 12.0 Hz, 1H), 5.04–5.10 (m, 2H), 5.34–5.36 (m,
2H), 5.58 (ddd, J = 10.0, 14.6 Hz, 1H), 6.97–8.04 (m, 27H). 13C NMR (100 MHz,
CDCl3) d (ppm) = 52.0, 58.1, 62.9, 69.8, 70.7, 71.4, 71.5 (d, J = 8.4 Hz), 71.7, 72.0,
3. Conclusions
In conclusion, we successfully accomplished the first chemical
synthesis of F-4-GlcAb(1?3)GlcNAc-UDP. During the course of
our synthesis, we have described a very efficient glycosylation
73.4 (d, J = 19.4 Hz), 77.6, 87.9 (d, J4 ,F = 185.4 Hz, C-40), 94.8, 97.9, 100.9, 153.2,
0
163.9, 164.4, 164.7, 165.3, 165.6. 19F NMR (323.6 MHz, CDCl3)
(ppm) = ꢁ122.13 (dd, JF,4 = 51.4 Hz, JF,3 = 16.4 Hz). MALDITOF-MS: calcd for
d
reaction which provides
a facile access to the desired F-4-
0
0
C55H47Cl3FNO16: 1101.19; found: 1124.51 [M+Na]+. Compound 2: ½a D25
ꢂ
+32.3 (c
GlcAb1?3 linked disaccharide with complete stereoselectivity
and high yield. We believe that this compound will serve as a novel
substrate to study the catalytic mechanism of HASs. The strategy as
described here could be extended to develop a novel assay for
these enzymes using synthetic acceptors/donors.
1.1, CHCl3); 1H NMR (400 MHz, CDCl3) d (ppm) = 1.83 (s, 3H), 3.41 (s, 3H), 3.89–
3.92 (m, 1H), 4.15–4.25 (m, 3H), 4.39–4.49 (m, 2H), 4.68–4.73 (m, 2H), 4.98–
5.11 (m, 6H), 5.71 (dd, J1,2 = 3.4 Hz, J1,P = 6.4 Hz, 1H, H-1), 5.78 (d, J = 9.2 Hz, 1H,
NHAc), 6.12 (ddd, J3 ,2 = J3 ,4 = 10.0 Hz, J3 ,F = 15.5 Hz, 1H, H-30), 6.90–8.04 (m,
30H). 13C NMR (100 MHz, CDCl3) d (ppm) = 23.2, 53.2, 56.1 (JC-2,P = 6.9 Hz, C-2),
62.1, 69.3 (JCH2Ph,P = 4.9 Hz, POCH2Ph), 69.5 (JCH2Ph,P = 4.9 Hz, POCH2Ph), 69.8,
71.7, 72.5 (CH, d, J = 8.8 Hz), 72.8, 73.8 (d, J = 19.8 Hz), 77.6, 86.9 (d,
0
0
0
0
0
J4 ,F = 186.2 Hz, C-40), 95.4 (JC-1,P = 6.1 Hz, C-1), 100.9, 163.9, 164.6, 164.7,
Acknowledgments
0
165.5, 168.6, 170.1. 19F NMR (323.6 MHz, CDCl3)
d
(ppm) = ꢁ121.32 (dd,
JF,4 = 52.2 Hz, JF,3 = 16.8 Hz). 31P NMR (202 MHz, CDCl3) d (ppm) = ꢁ1.91 (s, 1
0
0
We acknowledge grant support from DOD (W81XWH-06-1-
0013) and support, in part, by the NCI Cancer Center Support Grant
to the Roswell Park Cancer Institute (P30-CA016056). We wish to
thank Cheryl Krieger for her assistance in the preparation of this
manuscript.
P). MALDITOF-MS: calcd for C57H53FNO18P: 1089.30; found: 1112.61 [M+Na]+.
Compound 1: ½a 2D5
ꢂ
+12.5 (c 0.6, H2O); 1H NMR (400 MHz, D2O) d (ppm) = 1.93
(s, 3H), 3.51 (m, 1H), 3.62 (ddd, J3 ,2 = J3 ,4 = 9.6 Hz, J3 ,F = 15.6 Hz, 1H, H-30),
0
0
0
0
0
3.68–3.92 (m, 5H), 3.96 (dd, J5 ,4 = 9.2 Hz, J5 ,F = 2.6 Hz, 1H, H-50), 4.01 (ddd,
J2,1 = 3.6 Hz, J2,3 = 10.0 Hz, J2,P = 3.1 Hz, 1H, H-2), 4.08 (m, 1H), 4.15 (m, 1H),
0
0
0
0
0
0
0
4.16–4.18 (m, 1H), 4.23–4.26 (m, 2H), 4.35 (ddd, J4 ,3 = J4 ,5 = 9.4 Hz,
J4 ,F = 51.6 Hz, 1H, H-40), 4.51 (d, J1 ,2 = 7.9 Hz, 1H, H-10), 5.43 (dd, J1,2 = 3.2 Hz,
J1,P = 8.1 Hz, 1H, H-1), 5.82 (d, 1H), 5.85 (d, 1H), 7.85 (d, 1H). 13C NMR
0
0
0
References and notes
(100 MHz, D2O)
d (ppm) = 23.4, 57.2 (JC-2,P = 8.8 Hz, C-2), 62.8, 66.2 (d,
J = 3.8 Hz), 70.7, 70.9, 71.7, 74.5 (d, J = 8.8 Hz), 74.7, 75.8 (d, J = 19.8 Hz), 77.6,
1. (a) Williams, K. J.; Halkes, K. M.; Kamerling, J. P.; DeAngelis, P. L. J. Biol. Chem.
2006, 281, 5391; (b) Toole, B. P. Nat. Rev. Cancer 2004, 4, 528; (c) Toole, B. P.;
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P. W.; Bourguignon, L. Y. J. Biol. Chem. 2002, 277, 4589; (e) DeAngelis, P. L. Cell.
Mol. Life Sci. 1999, 56, 670; (f) Hall, C. L.; Turley, E. A. J. Neurooncol. 1995, 26,
221.
81.2, 85.0 (d, J = 9.8 Hz), 89.8, 93.9 (d, J4 ,F = 185.2 Hz, C-40), 96.8 (JC-1,P = 6.0 Hz,
0
C-1), 102.3, 103.8, 141.5, 153.4, 168.1, 174.5, 175.1. 19F NMR (323.6 MHz, D2O)
d (ppm) = ꢁ122.02 (dd, JF,4 = 50.2 Hz, JF,3 = 16.2 Hz). 31P NMR (202 MHz, D2O):
d: ꢁ11.2 (d, J = 23.8 Hz), ꢁ13.2 (d, J = 23.6 Hz). MALDITOF-MS: calcd for
C23H34FN3O22P2: 785.11; found: 783.95 [MꢁH]ꢁ.
0
0